From 191aab9fe8bfd149565a7ca6ac1dd60a69bcaba3 Mon Sep 17 00:00:00 2001
From: Drew Erny <derny@mirantis.com>
Date: Thu, 5 Nov 2026 08:53:09 -0600
Subject: [PATCH] cli/command/formatter: restore fallback for container names
 with slashes

Since commit f7a909d56b, ContainerContext.Names returns an empty string
when truncating and every name of the container contains a slash. Before
that change, all names were printed in that case.

Classic Swarm prefixes container names with the node-name
("/<node-name>/<container-name>"), so `docker ps` against a classic Swarm
API printed an empty NAMES column.

Restore the fallback to printing all names when no name without slashes
is found.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Drew Erny <derny@mirantis.com>
---
 cli/command/formatter/container.go      | 27 ++++++++++++++-----------
 cli/command/formatter/container_test.go | 19 +++++++++++++++++
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/cli/command/formatter/container.go b/cli/command/formatter/container.go
index 7b77a8a753..02d8110ad2 100644
--- a/cli/command/formatter/container.go
+++ b/cli/command/formatter/container.go
@@ -146,24 +146,27 @@ func (c *ContainerContext) ID() string {
 // slash (/) prefix stripped. Additional names for the container (related to the
 // legacy `--link` feature) are omitted when formatting "truncated".
 func (c *ContainerContext) Names() string {
-	var b strings.Builder
-	for i, n := range c.c.Names {
-		name := strings.TrimPrefix(n, "/")
-		if c.trunc {
-			// When printing truncated, we only print a single name.
-			//
-			// Pick the first name that's not a legacy link (does not have
-			// slashes inside the name itself (e.g., "/other-container/link")).
-			// Normally this would be the first name found.
-			if strings.IndexByte(name, '/') == -1 {
+	if c.trunc {
+		// When printing truncated, we only print a single name.
+		//
+		// Pick the first name that's not a legacy link (does not have
+		// slashes inside the name itself (e.g., "/other-container/link")).
+		// Normally this would be the first name found.
+		for _, n := range c.c.Names {
+			if name := strings.TrimPrefix(n, "/"); strings.IndexByte(name, '/') == -1 {
 				return name
 			}
-			continue
 		}
+		// No name without slashes was found; this can happen when connected
+		// to a classic Swarm API, which prefixes names with the node-name
+		// ("/<node-name>/<container-name>"). Fall back to printing all names.
+	}
+	var b strings.Builder
+	for i, n := range c.c.Names {
 		if i > 0 {
 			b.WriteByte(',')
 		}
-		b.WriteString(name)
+		b.WriteString(strings.TrimPrefix(n, "/"))
 	}
 	return b.String()
 }
diff --git a/cli/command/formatter/container_test.go b/cli/command/formatter/container_test.go
index 07df93d9ae..98e9be4c22 100644
--- a/cli/command/formatter/container_test.go
+++ b/cli/command/formatter/container_test.go
@@ -48,6 +48,25 @@ func TestContainerPsContext(t *testing.T) {
 			expValue:  "foobar_baz",
 			call:      ctx.Names,
 		},
+		{
+			container: container.Summary{Names: []string{"/other/link", "/foobar_baz"}},
+			trunc:     true,
+			expValue:  "foobar_baz",
+			call:      ctx.Names,
+		},
+		{
+			container: container.Summary{Names: []string{"/foobar_baz", "/other/link"}},
+			expValue:  "foobar_baz,other/link",
+			call:      ctx.Names,
+		},
+		{
+			// Names returned by a classic Swarm API are prefixed with the
+			// node-name; see https://github.com/docker/cli/pull/6875
+			container: container.Summary{Names: []string{"/node-1/foobar_baz"}},
+			trunc:     true,
+			expValue:  "node-1/foobar_baz",
+			call:      ctx.Names,
+		},
 		{
 			container: container.Summary{Image: "ubuntu"},
 			trunc:     true,